Process and system for gathering and evaluating measured data

ABSTRACT

A process and a system for multi-channel gathering and evaluation of measured data in which measured data channels are distinguished into analog data channels and into digital or event channels. By means of a signal derived from the events, or rather from event signals, and processed in the event channels the analog measured data are synchronously sampled, (i.e. picked up, converted into a digital value and stored). Each time an identification number is stored for the event signal triggering the sampling operation, or rather of the corresponding event channel, the phase time between this sampling signal and the preceding sampling signal, the associated sampled measured data and the time sequence of the sampling operations. The signal triggering the synchronous sampling operation is preferably formed by OR-linking of all event signals which are scaled down, if applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a process for multi-channel gathering andevaluation of measured data where analog measured data are picked up inparallel measured data channels, are converted into digital measureddata and are stored in a memory for on-line or off-line evaluation. Alsoincluded in the subject matter of this invention is a system withmeasured data channels which are operated in parallel and which areindependent of one another, namely with analog data channels, providedwith individual analog-to-digital converters or with multiplexers havingone common analog-to-digital converter at a time and with memories; withdigital measured data channels, or rather with so-called event channels;as well as with circuits for controlling the gathering of the measureddata.

DESCRIPTION OF THE PRIOR ART

Systems for multi-channel gathering and evaluation of measured data arealready known (essay by M. Vieten, "Erfassung schneller Meβsignale mitdem Personal-Computer" Gathering fast measured signals by means of thepersonal computer, Elektronik, Heft volume 4/1986). Such systems, interalia, are used in automotive engineering both for driving tests and forrealizing digital multi-variable control units.

The measured value gathering systems, known by the term "transientrecorders," are composed of a plurality of independent measured datachannels operated in parallel. In general, each measured data channel isallocated a preamplifier stage of its own, an analog-to-digitalconverter of its own, and a data memory of its own. In principle, eachchannel is an individual device, with the special feature that allchannels operate synchronously and are jointly controlled. For thepurpose of gathering measured data, a momentary value of the signalapplied to the measured data channel input is sampled in all channels inequidistant time steps, i.e., it is picked up and processed. Afteranalog-to-digital conversion, the numerical values corresponding tothese measured values are stored in a memory. Depending on the type ofapplication or on the version of the system, the sampled values remainin the memory until "off-line" evaluation of the measured data, or theyare further processed "on-line" at once; if so, they are overwritten bynew data after a certain cycle time. A variety of different versions ofapparatuses use this principle. For instance, instead of using oneanalog-to-digital converter at a time for each channel, it is possibleto feed the analog measured data to a common analog-to-digital convertervia a multiplexer in order to reduce cost. As the measured data have tobe processed consecutively, this technique implies a lengthenedprocessing time.

In these known measured data gathering systems working in accordancewith the transient recorder concept, a sequence of numbers, or rather asequence of measured values, is always gained as a function of time.This implies restrictions in case of technical operations wherereference to time does not play any role or is only of minor importanceand where the sensor used for generating the measured data is theincremental type. Then the information available from measuring is notin the signal amplitude but is contained in the alternating edges ofbinary signal conditions. For instance, the alternating edges of thesignal at the output of a wheel speed sensor of an anti-skid controlsystem mark the rolling angle and are independent of whether the wheelrotates quickly or slowly. In this case, time-equidistant sampling ofthe amplitude is particularly disadvantageous as it is necessary to workwith a high sampling rate in order to detect the time of alternatingedges with sufficient accuracy, although later on only one value will beevaluated, namely the time of alternating edges. Therefore, in such anapplication counters are often used which register the number ofalternating edges occurring during one sampling interval. This number isthen stored as the measured value. Thereby it is, admittedly, possibleto save memory locations and to simplify evaluation; however, thereremains the disadvantage that the phase relationship between thedifferent events cannot be reconstructed, or rather is not evaluatable,any longer in order to gain certain information. As the measurements arebased on the same time base, the resolution of the measured contents andthe time required for measuring are extremely dependent on the wheelspeed.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to overcome theaforementioned disadvantages and to provide a process as well as asystem for multi-channel gathering and evaluation of measured data whichwill be suitable for gathering analog and digital measured signals, inparticular in the field of incremental measuring techniques, and whichexcels by high measuring precision, by high data reduction economy and,implied thereby, by a high storage economy as compared with transientrecorders.

It has been found that this object can be achieved by means of a processof the type referred to above whose particular feature is that themeasured data channels are distinguished or divided into analog datachannels and into digital or so-called event channels. The analog dataare synchronously sampled, i.e., picked up, processed (converted) andstored, by means of a signal derived from the events and processed inthe event channels. The phase time between two subsequent samplingsignals is measured and each time there are stored an identificationnumber of the event signal triggering the sampling operation, (i.e., thecorresponding event channel), the phase time between this samplingsignal and the preceding one, the associated sampled values, (i.e., thesampled measured data), and the time sequence of the samplingoperations.

A system for implementing this process of gathering and evaluatingmeasured data is distinguished in that the pick-up, the processing orfurther handling and the storage of the measured values present in theindividual analog data channels is synchronously controllable by meansof a sampling signal derived from the event signals. The sampling signalfurther is fed to a channel decoder identifying the event channel of theevent triggering the control signal, as well as to a phase timemeasuring unit detecting the time duration between two subsequentsampling signals. Each time a sampling signal comes up, the system canstore the identification number (such as the number of the triggeringevent channel), the phase time between the preceding sampling signal andthe latest one as well as the associated sampled values and the timesequence of the sampling operations.

Thus, an essential feature of this invention is the control of datagathering or sampling dependent on "events". Thereby decisive advantagesare achieved as compared with the conventional transient recorderprinciple. As will become evident in more detail from the following, bymeans of corresponding linking and evaluation, it is possible to derivevarious information and measured values with a high degree of precision,as yet unrivalled, from the data stored according to this invention in apredetermined arrangement and sequence in the memory. At the same time,the capacities of the conventional transient recorder will bemaintained. It is namely possible to include a "transient recordertrack" at one input of the event channels by means of equidistant timesignals; consequently, a transient recorder is one embodiment of theinvention for gathering and evaluating measured data. In contrast to thetransient recorder, however, it is possible to use not only the time assampling quantity but also, additionally, any other sequence of events.For instance, the increments of the driven distance of a pulse wheel ofan anti-skid control system or the signals of a Peiseler wheel may serveas event signals. According to this invention, the phase time betweentwo subsequent pulses, representing the events in this case, aremeasured continuously. Independently of the driving speed, thecomputation of the instantaneous speed is always related to a distanceunit of unchanging size. As it is possible to measure the phase timevery precisely without great efforts the resolution of the measurementand the accuracy of the measurements now only depend on the quality andon the fineness of the incremental transducer. Because of taking adistance increment as a sampling interval, the sampling rate isautomatically adapted to the driving speed. This will be of greatadvantage if measurements are to cover large measurement ranges such asis the case during driving tests. According to one embodiment of thisinvention, a system was constructed for gathering the measured data of avehicle by means of which it was possible to measure instantaneousspeeds, related to 1/1000 of rolling circumference, with 0.1% accuracywith driving speeds between 0.02 and 200 km/hr. Such a degree ofaccuracy is necessary in order to make use of the quality of 1%-classtransducers. With the same degree of accuracy, according to thisinvention, it is also possible to determine driven distances, phases ofposition, twisting angles, linear movements or wheel slip relations and,simultaneously, to allocate the measured signals of analog channels tothese data. Due to the high instantaneous value resolution it ispossible to make visible even small changes, or rather fine details, andto alternatively represent them as a function of the driven time or ofthe driven distance.

According to one advantageous embodiment of this invention, the eventchannels have individual signal processing stages followed by event ratescaling-down units. The sampling signal is preferably formed byOR-linking of all event signals that have been processed and, ifapplicable, scaled down.

The phase time measuring unit of one embodiment of this inventioncontains a central counter which is reset and restarted by any eventsignal that has been processed and, if applicable, scaled down, eachtime the counter contents are transferred as phase time into the memory.

In a further embodiment, the invention is equipped with input stages ofthe same kind which comprise an input amplifier or preamplifier and achange-over device each of whose input signals are evaluatable as analogdata and/or as event signals, depending on the operating position of thechange-over device. Advantageously, additional signals, indicating thedirection or the sign of a signal change, and marking signals--such asfor zero marking--are fed to the input stages.

Further characteristics, advantages and applications of this inventionwill become evident from the following description of further detailsand from the accompanying illustrations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of the fundamental structure of a gatheringand evaluation system for measured data in accordance with thisinvention;

FIG. 2 is a further embodiment of the invention shown in FIG. 1.

FIG. 3 shows a storing scheme for the measured data of the systems ofFIG. 1 or FIG. 2;

FIG. 4 Shows an example of data gathered by means of the invention--theform of representation being a time-continuous data chain;

FIG. 5 shows an example similar to FIG. 4 with additional illustrationof the sampled values of an analog data channel;

FIGS. 6A-9 show some examples for explaining the evaluability of thestored data, the representation being the same as in FIGS. 4 and 5 withadditional diagrams (FIGS. 6A-8B);

FIG. 10 is a diagram illustrating the evaluation procedure referred toas "channel sequence";

FIG. 11 is a similar illustration as FIG. 10 with evaluation of thecentral counter overflow; and

FIGS. 12A-12B shown an example of an embodiment of the invention where,additionally, the direction and a marking have to be taken intoconsideration for evaluating the signals.

DESCRIPTION OF THE PREFERRED EMBODIMENT

According to FIG. 1, this embodiment of a system for gathering measureddata consists of a plurality of parallel analog data channels A(1),A(2), A(n), of event channels E(1), E(2), E(n), of a control part forgenerating a sampling signal 4 and of a memory with the analog datasection 3 as well as with the memory locations 10, Il, 12 for thechannel sequence (10), for the phase times (11) and for the sequence ofevents (12).

The analog measured data are fed to one analog-to-digital converter 2(2₁,2₂, . . . 2_(n)) at a time via preamplifiers 1 (1₁, . . . 1_(n))associated with the individual channels. In accordance with anotherembodiment of this invention (not illustrated), a commonanalog-to-digital converter, instead of the individual analog-to-digitalconverters (2₁, 2₂, . . . 2_(n)), is connected to the outputs of thepreamplifiers 1₁. . . 1_(n) via a multiplexer. The values provided bymeans of the analog-to-digital converter(s) are transferred into thememory section 3 via a multiplexed line 13.

The inputs E(l) through E(n) of the event channels are followed by ablock with the signal processing stages 5 associated with the individualevent channels. The event signals are scaled down with the factors1/K(l). . . 1/K(n) in an event rate scaling-down unit 6. As in manyapplications, in particular with regard to efficient memoryexploitation, it is an advantage to evaluate only the K^(th) eventsignal of a sequence of event signals as an effective event fortriggering the sampling of the measured data. For instance, if anincremental distance transducer, connected to one of the event channelinputs E(n), delivers one pulse per millimeter of locomotion and if thescaling-down is set to be K=10, the effective event rate will be 1centimeter. After having passed the event rate scaling-down unit 6, theeffective events of all connected event channels E(n) are linked in alogical OR-stage 7 and will then jointly form the already mentionedsampling signal or control signal 4. In the present instance, a timebase 14 such as the output signal of a clock or of a clock generator isconnected to one of the inputs of the event channels, namely to inputE(l). Thereby a time-periodical share is included in the control signal4, which signal, in terms of time, is aperiodical. The time-periodicalshare generates a so-called "transient recorder track" within the analogdata picked up, i.e., sampled, and stored in the memory system.

Essential components of the invention are a channel decoder 8 and aphase time measuring unit 9 both connected in parallel with theanalog-to-digital converter 2 at the output of the OR-stage 7. Thus, theconverter 2, the channel decoder 8 and the phase time measuring unit 9are simultaneously actuated by means of any control signal or samplingsignal 4. The channel decoder 8 has the effect that the identificationnumber, or rather the associated channel number, will be ascertained forany effective event signal and will be stored as a channel sequence insection 10 of the data memory. The phase time measuring unit 9 measuresthe phase time between two subsequent events and stores thecorresponding information as phase time in section II of the datamemory. The phase time measuring unit 9 consists of a time base A and ofa counter referred to as central counter in this case. The centralcounter 9 is reset and restarted upon any new incoming event signal ofwhatever channel origin and the contents of the counter, accumulateduntil that moment, are registered. Multiplied with the interval of timebase A, there results the phase time which then is stored in section IIof the data memory. The channel sequence and phase times areadvantageously allocated in such a manner as to register the respectivelast phase time in combination with that channel number which hastriggered the restart of the central counter. Thus, there results thevertical and horizontal allocation, represented in FIG. 1, of the datastored in the memory.

The phase time representing the time distance between two events can bedetermined very accurately in a simple way since only a fast-actingcounter with a counting volume sufficient for the largest time distanceof subsequent events is needed for this purpose.

In the embodiment of the invention represented in FIG. 2 only inputstages 16, 17 of the same kind are provided beside one sole time base 15which, just like time base 14 of FIG. 1, serves to form a "transientrecorder track". Via a channel selection device 18 controlling thechange-over devices 19, 20, the signal applied to the signal inputs S₁,. . . S_(n) of the input stages 16, 17 is evaluated either as an analogsignal or as a digital signal, or rather as an incremental event,depending on the operating position of devices 19, 20. Via preamplifierstages, the input signals S₁, . . . S_(n) each is fed toanalog-to-digital converter 23, 24 and to a signal processing stage 25,26 which is connected in parallel with the converter and which also hasan event rate scaling-down unit 27, 28. Consequently, the preamplifiers21, 22 as well as the converters 23, 24 belong to the analog datachannels. The preamplifiers 21, 22 likewise belong to the event channelsas do the signal processing stages 25, 26 and the event ratescaling-down units 27, 28. The preamplifiers 21, 22 serve to process thetwo types of signals--the analog data and the event signals.

Depending on the operating position of the change-over devices 19, 20,the incremental share of the input signals S₁, . . . S_(n) issimultaneously evaluated as an event signal or--with the switch (19, 20)open--only the analog signal is processed.

The individual input stages 16, 17 have additional inputs M₁, . . .M_(n) ; R₁, . . . R_(n) which lead to the signal processing circuits 25,26 of the event channels, by means of which it is also possible to feedthe direction of a signal change (R₁, . . . R_(n)) and/or a mark such asa zero mark (M₁, . . . M_(n)).

For the rest of the system components, the embodiments as shown in FIGS.1 and 2 are the same, which is expressed by the corresponding referencenumerals 3', 4', 7' through 13'.

In the embodiment shown in FIG. 2, the time base 15 acts as anintegrated switch-on event channel and furthermore supplies the centralcounter of the phase time measuring unit 9' with counting pulses. Thechannel decoder 8' also takes into consideration the direction, orrather the sign of direction, as well as the appearance of markingsignals in addition to the channel information. Besides, the channeldecoder 8' also reacts to overflow marks of the central counter which issymbolized by the arrow 29. In addition to the channel sequence,directions and markings are taken into consideration in section 10, ofthe memory system. This fact is indicated in the drawing by the symbols+, -, M.

In a slightly changed representation, FIG. 3 again illustrates thescheme in accordance with which the measured data are stored in order toenable an allocation of the sampled signal values to a certain event, acertain sequence of events or any other certain instant in time withinthe scope of the signal evaluation explained in even more detail in thefollowing.

FIGS. 4 and 5 illustrate the selection and sequence of the data gatheredand stored in accordance with the invention. In FIG. 4, the stored data,namely the channel identification numbers, or rather the channelnumbers, and the phase times are illustrated in the form of atime-continuous data chain. FIG. 5 additionally also shows the measuredvalues gained by means of an analog measured data channel and sampledand stored dependent on the "events".

In accordance with FIGS. 4 and 5 the same event interval is used betweentwo like channel numbers. For instance, the event intervals of channel 2could each correspond to a distance increment L=constant while theevents transferred in channel 1 originate from a time base (time base 14or 15 as shown in FIG. 1 or FIG. 2), with T=constant. FIGS. 4 and 5illustrate that the conventional operation with constant time samplingrate is only a special case of the process and of the system inaccordance with this invention. Of particular importance is that theexact phase relationships of all events are reconstructible forevaluation of the measured signals.

FIG. 5 shows the sampling of the measured values, or rather of thesignal amplitudes, of an analog data channel by means of the eventsignals occurring in irregular sequence. For the sake of clarity, onlyone analog data channel is represented here. As a rule, there areseveral analog data channels which are sampled in parallel andsynchronously, as described with reference to FIGS. 1 and 2. If thereare several events in one time period defined by one sole centralpredetermined counter increment, these events will be treated asisochronous. What is registered is the multiple appearance of eventswithout mutual phase time. An example of such a case is traced in FIG. 5for the event channels 2/4/6. The known laws of "Shannon" describing theminimum requirements with regard to the sampling rate are also adheredto in the present instance when determining the central counter rate.

FIGS. 6A and 6B illustrate the structure of an analog channel evaluationon the basis of events of channel 2. By way of example, it is hereassumed that these events are derived from the pulse wheel of a wheelspeed sensor as used in automotive vehicles for anti-skid control, forexample. Thus, by relating them to the wheel circumference, these eventswould be distance increments. In order to illustrate an analog operationas a function of the driven distance (position), the channel sequence issearched for the appearance of channel number 2 and the analog value,sampled and stored with regard to this event, is allocated. In thepresent instance that event channel which is the object of the searchingoperation (channel number 2) is termed "reference channel". At the sametime, this channel is graphically allocated the X-axis (FIG. 6B). Theother channel (analog channel or event channel) related to the referencechannel is termed "related channel". In FIG. 6A, the Y-axis is allocatedto this channel. Evaluating operations where sampled analog values areallocated to the reference channel events will here be given the term offunction "FCT" (German abbreviation: "FKT").

FIGS. 7A and 7B show the mode of operation of a conventional transientrecorder is achieved by means of the inventive process (in addition tothe other possibilities of evaluation). To this end, the signals of atime base (time base 14 in FIG. 1) are fed to an event channel uponpick-up. During the subsequent FCT procedure, this channel is selectedas reference channel. In FIG. 7B, this is channel 1. The time event isrecognized by the constant sum of phase times between the referencechannel numbers.

There are numerous further possibilities of evaluating the valuesgathered and stored in accordance with the inventive process. Accordingto a procedure of evaluation, which is referred to as SUM/XREF and whichis explained with reference to FIGS. 8A and 8B, two sequences of eventsare correlated. In the illustrated example, channel 3 is the referencechannel and channel 2 is the related channel. The system counts howoften a related-channel number appears per reference channel interval,this figure being balanced with the preceding value. Proceeding from astarting point, there will thus result the increment of the relatedevents as a function of the increments of the reference channel. Forinstance, if the reference channel events are images of a wheel speedsensor pole wheel, arranged at the left front wheel of an automotivevehicle, and the related-channel events are those of a like pole wheelat the right front wheel, it is possible in this manner to directlyillustrate the travel difference of the wheels of one axle duringcornering of the vehicle.

FIG. 9 relates to a procedure of evaluation referred to in this contextby GESCHW (SPEED). It serves to compute and illustrate the momentaryvalues of the event speed. To this end, the event interval of thechannel under observation (channel 3 in the present example) is dividedby the sum of the associated phase times. This operation corresponds tothe formation of a time difference quotient with equal numeratordifferences, yet unequal denominator differences. By means of thisprocedure and the inventive process of determining the channel sequenceand the phase time, the user has a simple means at hand in order to beable to determine accurate momentary speed values even in case ofrougher pitch pulse generators (e.g., in case of pulse wheels ofconventional wheel speed sensors of antiskid control systems), withoutthe extent of memory locations and measuring time normally required forthis purpose.

A procedure of evaluation called KANALFOLGE (CHANNEL SEQUENCE),explained with reference to FIG. 10, makes visible the sequence of theincoming events. To this end, the respective last phase time is tracedas a function of that channel number which restarts the central counter.Events at different channels, which appear simultaneously within thephysically implied resolution time, are recorded as parallel-appearingevents with several channel numbers. KANALFOLGE (CHANNEL SEQUENCE) iswell suited for analyzing measuring mistakes (e.g., a central counteroverflow) and for making visible rhythmic event movements (such asfrequency modulations).

The versatility of the inventive process can be explained with referenceto another simple example. It is intended to ascertain the variation ofthe vehicle speed during a braking operation as a function of thebraking distance, on the one hand and as a function of the driven time,on the other hand. The pulse wheel of a wheel speed sensor of ananti-skid control system serves as distance transducer. The signals ofthe sensor are applied to an event channel, channel 5 for instance.Additionally, the signals of a time base with a sufficiently highsampling rate are connected to another event channel, e.g., to channel4. The GESCHW (SPEED) procedure of evaluation then directly supplies therepresentation of the vehicle speed as a function of the brakingdistance. If channel 5 is selected as reference channel and channel 4 asrelated channel, in an intermediary step, the SUM/XREF procedure (seeFIG. 8A) supplies the time as a function of the braking distance. In asubsequent XY procedure (X=SUM/XREF; Y=SPEED) the braking distanceserves as linking quantity, and there results the second desiredrepresentation, namely the speed as a function of the driven time.

Further, it is possible to write an overflow mark into the channelsequence by means of he overflow of the central counter and subsequentlyto restart the central counter at once (see FIG. 2). The overflow resultnow can be evaluated like any normal event signal. This has theadvantage that the central counter is always able to work at the highestspeed (with the highest resolution), without the fear that a centralcounter overflow might render the measurement unusable. Technically, itis possible to operate the central counter with a frequencycorresponding to an integral multiple of the physically implied timerequired for setting the overflow mark. When evaluating the mark, it ispossible to add again the increment corresponding to the setting mistakeand thus to substantially compensate for the time mistake which is veryslight. FIG. 11 illustrates a channel sequence with overflow marks P.

As already explained with reference to FIG. 2, it is also possible totake the "direction" of events into consideration. The drivingdirection, forwards or rearwards, plays a role in many technicalsituations such as during automotive vehicle driving tests. In othertechnical operations, the direction may change in respect of a referencecondition. Incremental transducers available for measuring purposes areprepared for this requirement and deliver identification signals, besidethe event signal, for the direction and for marking reference pointssuch as the zero point. Instead of a direction signal, two event signalsoffset by 90° are delivered in some cases, the signals allowing thedetermination of the direction of movement. In the embodiment of theinvention shown in FIG. 2, this now is simply taken into considerationin that the event direction is included in the channel sequence as achannel sign, and a marking input is provided as an additional,specially identified channel. FIGS. 12A and 12B show an example of achannel sequence which is gained from a pendulum motion by means of asuitable incremental transducer working on channel 3. The phase timesare traced as neutral amounts. The reversal of the direction of thependulum, chosen to be positive, is expressed by the negative sign ofthe channel number. The marker is traced as an additional channelidentified as M3. The fundamental procedures of evaluation describedabove change only in that, during computation, a sign is considered, orrather in that additional relative conversions are carried out withregard to the position of the marker. Of course, a marker can also be areference channel for other related channels. Those skilled in the artwill have no difficulty in adapting the inventive process to theirrespective applications.

In the following, a description is given of a concrete example of anembodiment of the system for gathering and evaluating measured data, asshown in FIG. 1.

In this case, the system had 12 analog channels each of which wasequipped with a 12-bit resolution analog-to-digital converter of itsown. There were 8 event channels and one time base (14) which, incombination with one of the event channels, served to feed time eventsinto the channel sequence. The time base worked within a range of 2cycles up to 200 kilocycles per second. The event rate scaling-downunits (6) were adjustable from 1 to 256. A 12-bit wide central counterwith a time base of its own, ranging from 2 cycles up to 200 kilocyclesper second, was provided for measuring the phase times. Each analogchannel as well as the channel sequence memory section (10) wereallocated a RAM-type memory of its own with a 128-kB-measured-datacapacity so that 128,000 events could be recorded altogether. Thegathering of measured data could alternatively be started by theappearance of an event signal or by a signal feedable by hand andstopped by hand at any time. If the sum of the incoming signal eventsreached a number of data memory locations, predetermined as a block,measurement was automatically interrupted.

Gathering, storage, evaluation and display of the measured data werecomputer-assisted. A software program containing all the above-describedprocedures was used for evaluating the channel sequence.

Further examples of applications of the invention are described belowwith reference to a test vehicle equipped with (wheel speed) sensors andwith the inventive measured data gathering system. Braking pressures,bump travels etc. were measured via the analog channels. Connected tothe event channels were wheel speed pulse generators (Peiseler wheels)generating 1000 pulses per revolution and thus capable of resolving therolling distance up to approximately 1.6 mm. The following list includessome of the possible measurement configurations:

Measurements as a function of the driven distance (position):

Occupancy: 1 event channel with a wheel pulse generator with an eventrate scaling-down of K=250; all 12 analog channels;

Applications: measurements along a distance of approximately 50 km, withany driving speed (temporarily even zero speed) and with a sampling ofthe analog data channels approximately every 40 cm.

Occupancy: 5 event channels, namely four wheel pulse generators with anevent rate scaling-down of K=1; 1 driving speed transducer;

Applications: measurement of driven distance and wheel rolling distanceswith 1.6 mm accuracy; at the same time, gathering of instantaneousvalues of vehicle and wheel speeds, or rather wheel slip measurementswith similar resolution.

Measurements as a function of time:

By means of setting the central counter speed the maximum timeresolution can be 0.025% of the event period in case of events with, onaverage, constant event speed. This applies to period durations of 10milliseconds up to 2000 seconds.

Occupancy: 1 event channel with the internal time base (14 in FIG. 1);all 12 analog channels.

Applications: a 12-channel transient recorder is formed with a128-kB-measured-data capacity per channel, which recorder is to beoperated with a sampling frequency of 200 kilocycles.

According to one variation of the described embodiment, four analogchannel input stages were fed each to one common analog-to-digitalconverter via a multiplexer. An alternating buffer was used to generatea continuous flow of measured data to a mass storage. In this case, themeasured data gathering system had two smaller RAM-type memories(buffers) organized in the same way. While the first buffer picked upmeasured data, the second one transferred the data to the mass storageand vice versa.

In this way, it was possible to transfer the data on the channelsequence, phase time etc.--beside the sampled analogvalues--continuously to a large capacity mass storage.

The basic idea of the described inventive process and of the principleof the corresponding system for gathering and evaluating measured datathus are that the "events" of all incremental sensors connected to theevent inputs and, if applicable, the pulses of an additional internaltime base trigger a sampling operation in the time sequence of theirappearance in a manner which may be scaled down, if applicable. Therebyall analog signal channels are synchronously sampled in the way of aflash photograph. As the events are not synchronized with regard totime, sampling is non-equidistant as a rule. If, furthermore, a timebase is connected whose time signals are equidistant, then a transientrecorder track, as it were, is superimposed on the measuring operation.In combination with sampling of the measured data applied to the analogdata channels, the channel sequence in which the sampling operations aretriggered and the time interval (phase time) which has passed betweentwo sampling events are simultaneously registered. The measured datathen will be stored in accordance with a scheme illustrated in aparticularly clear way in FIG. 3 so that the subsequent allocation ofthe sampled signal values to a certain event, a certain sequence ofevents or to a certain time is possible.

What is Claimed:
 1. A method for gathering and making available forevaluation measured data comprising the steps of:supplying, from aplurality of parallel and independent analog data channels and aplurality of event channels, analog data signals and event data signalsrepresentative of measured data, said event data signals havingidentification numbers corresponding to the event channels with whichsaid event data signals are associated; generating successive samplingsignals in response to event data signals from at least one eventchannel; sampling analog data signals from the analog data channelssynchronously in response to each sampling signal and converting sampledanalog data signals into digital data signals representing digitalmeasured data; measuring a time interval between successive samplingsignals; determining the identification number for the event channelproviding the event data signal which causes generation of the samplingsignal; and storing the time interval, the digital measured data, andthe respective identification number, for each sampling operation andmaking availalable for evaluation the stored digital measured data.
 2. Amethod as set forth in claim 1, wherein the step of generatingsuccessive sampling signals comprises the steps of:assigning each eventchannel to one of first and second groups; generating a sampling signalin response to each event data signal received from an event channel insaid first group; counting the number of event data signals receivedfrom each individual event channel in said second group; and generatinga sampling signal for each individual event channel in said second groupwhen a predetermined number of event data signals are received from saidchannel.
 3. A system for gathering and making available for evaluationmeasured data comprising:means, including a plurality of parallel andindependent analog data channels and a plurality of event channels, forsupplying analog data signals and event data signals representative ofmeasured data, said event data signals having identification numberscorresponding to the event channels with which said event data signalsare associated; means for generating successive sampling signals inresponse to event data signals from at least one event channel; meansfor sampling analog data signals from the analog data channelssynchronously in response to each sampling signal and for convertingsampled analog data signals into digital data signals representingdigital measured data; means for measuring a time interval betweensuccessive sampling signals; means for determining the identificationnumber for the event channel providing the event data signal whichcauses generation of the sampling signal; and means for storing the timeinterval, the digital measured data, and the respective identificationnumber, for each sampling operation and for making availalable forevaluation the stored digital measured data.
 4. A system as set forth inclaim 3, wherein said sampling signals generating means include meansfor generating a clock signal which is coupled to one of the pluralityof event channels.
 5. A system in accordance with claim 3, wherein saidsampling signal generating means include:means for counting the eventdata signals from each individual event channel; and means forgenerating a sampling signal for each individual event channel when apredetermined number of event data signals have been counted for thatevent channel.
 6. A system as set forth in claim 3, wherein saidsampling signals generating means include:means for assigning each eventchannel to one of first and second groups; means for generating asampling signal in response to each event data signal received from anevent channel in said first group; means for counting the number ofevent data signals received from each event channel in said secondgroup; and means for generating a sampling signal for each event channelin said second group when a predetermined number of event data signalsare received from said channel.
 7. A system in accordance with claim 3wherein said time interval measuring means include:means for supplyingclock signals; means for counting said clock signals; means responsiveto said sampling signals for conducting to said storing means the countof said clock signals each time a sampling signal is generated and forresetting said counting means each time a sampling signal is generated.8. A system for gathering and making available for evaluation measureddata comprising:means, including a plurality of parallel and independentchannels, for supplying analog data signals and event data signals, saidevent data signals having identification numbers corresponding to thechannels with which said data signals are associated; means forallocating each independent channel as one of event and analog datachannels, corresponding to the data supplied by said channels; means forgenerating successive sampling signals in response to event data signalsfrom at least one independent channel allocated as an event channel;means for sampling analog data signals from the independent channelsallocated as analog data channels synchronously in response to eachsampling signal and for converting sampled analog data signals intodigital data signals representing digital measured data; means formeasuring a time interval between successive sampling signals; means fordetermining the identification number for the independent channelproviding the event data signal which causes generation of the samplingsignal; and means for storing the time interval, the digital measureddata, and the respective identification number, for each samplingoperation and for making availalable for evaluation the stored digitalmeasured data.
 9. A system in accordance with claim 8 furthercomprising:means for supplying direction signals representative of adirection of change for the analog measured data; and means forsupplying reference signals representative of reference values for saidanalog measured data, andwherein said storing means store and makeavailalable for evaluation said direction and reference values.
 10. Aprocess for multi-channel gathering and evaluation of measured datawhere analog measured data are picked up in parallel measured datachannels, are converted into digital measured data and are stored in amemory for on-line or off-line evaluation, with the analog measured datain the parallel measured data channels being synchronously sampled by adigital sequence of signals or sequence of events, characterized in thatthe measured data channels are distinguished or divided into analog datachannels and in digital or so-called event channels, in that thesynchronous sampling, i.e. picking-up, processing and storing of themeasured data obtained in the analog measured data channels iscontrolled by way of the signal (4, 4') derived from the events andprocessed in the event channels, in that the phase time (t_(nm)) betweentwo subsequent sampling signals is measured, and in that each time thereare stored an identification number of the event signal triggering thesampling operation, or rather of the corresponding event channel, thephase time (t_(nm)) between this sampling signal and the preceding one,and the appertaining sampled values or sampled measured data (A(nm)).11. A process as claimed in claim 10, characterized in that the samplingsignal (4, 4') is formed by OR-linking of event signals and/or of eventsignals scaled down.
 12. A system for implementing the gathering andevaluation of measured data, with measured data channels which areoperated in parallel and which are independent of one another, namelywith analog data channels, provided with individual analog-to-digitalconverters or with multiplexers having one common analog-to-digitalconverter at a time and with memories; with digital measured datachannels or with so-called event channels; as well as with circuits forcontrolling the sampling operation and the gathering of the measureddata, characterized in that the pick-up, the processing or furtherhandling and the storage of the measured values present in theindividual analog data channels is synchronously controllable by meansof a sampling signal (4, 4') derived from the event signals; in that thesampling signal further is feedable to a channel decoder (8, 8')identifying the event channel of the event triggering the samplingsignal as well as to a phase time measuring unit (9, 9') detecting thetime duration (t_(nm)) between two subsequent sampling signals (4, 4');and in that each time a sampling signal (4, 4') comes up there can bestored the identification number such as the number of the triggeringevent channel and the phase time (t_(nm)) between this sampling signaland the preceding one as well as the appertaining sampled values.
 13. Asystem in accordance with claim 12, characterized in that there isprovided an event channel which a time base (14, 15) is connected to.14. A system in accordance with claim 12, characterized in that theevent channels have individual signal processing stages (5, 25, 26)followed by event rate scaling-down units (6, 27, 28).
 15. A system inaccordance with claim 12, characterized in that the sampling signal isformed by OR-linking (OR-stage 7, 7') of all event signals that havebeen processed or, if applicable, scaled down.
 16. A system inaccordance with claim 12 characterized in that the phase time measuringunit (9, 9') contains a central counter which is reset and restarted byany event signal that has been processed and, if applicable, scaleddown, each time the counter contents being transferable as phase timeinto the memory (11, 11').
 17. A system in accordance with claim 12,characterized in that the same is equipped with input stages (16, 17) ofthe same kind which comprise an input amplifier or preamplifier (21, 22)and a change-over device (19, 20) each and whose input signals areevaluatable as analog data and/or as event signals, depending on theoperating position of the change-over device (19, 20).
 18. A system asclaimed in claim 17 characterized in that additional signals (inputs R1,R2), indicating the direction or the sign of a change, and markingsignals (inputs M₁, M₂)--such as for zero marking--are feedable to andevaluatable in the input stages (16, 17).